The present invention relates to precision machine tools for machining flat parts of different materials.
More particularly, it relates to precision grinding of parts composed of glass, ceramic, semi-conductors and other materials.
Machine tools of the above-mentioned general type are known in the art. Such machine tools is disclosed for example in Soviet inventor's Certificates Nos. 390,924 and 622,650. They are used for grinding flat parts and include a rotary table with a changeable flat plate for attaching parts to be machined on its base surface, and a rotatable abrasive tool. The machine tools disclosed in these references have an orientation mechanism which is in contact with the base surface of the pivotal flat area of the changeable flat plate. The orientation mechanism includes two rings with bearing balls located between them. One ring is non-rotatable, while the other ring rotates in contact with the pivotal area of the flat blade. The above-mentioned machine tools have certain disadvantages. The device is limited to the sizes of the rings and do not allow building of orientation mechanisms of greater dimensions with flatness on the rings about 1 micron or less, since greater diameters require greater flatness tolerances of the parts to be machined. It is advisable to improve the machines tools of this general type.